Spring 2001, CSE 428: Quiz 1.4 - 18 Jan 2001

Solution

  1. The right answer is 5: The language of all the strings of the form   ab, abab, ababab,   etc.

  2. The right answer is 4: A grammar is ambiguous if there are two different derivation trees for the same string

    1. "-" is right associative false
    2. "^" has precedence over "-" true
    3. The grammar is ambiguous false

    1. 2 ^ 2 ^ 2 is derivable
    2. 16 is not derivable 

  5.           A
          |
          B
         /|\
        / | \
       C  ^  B
       |    /|\
       |   / | \
       1  C  ^  B
          |     |
          2     C
                |
                0